有什么用例,没有UI中的片段? [英] What is the use case for a Fragment with no UI?
问题描述
Android开发指南对使用碎片一个体面的部分。使用片段的方法之一是没有的UI。有几个参考使用此作为后台处理的手段,但是优势并片段为这一领域?我会在哪里选择使用片段在线程,AsyncTasks,处理程序等,为后台处理?
The Android Developer guide has a decent section on the use of Fragments. One way to use Fragments is without a UI. There are a few references to using this as a means of background processing, but what advantages do Fragments bring to this area? Where would I choose to use a Fragment over Threads, AsyncTasks, Handlers, etc. for background processing?
推荐答案
A 片段
实例可以通过设备配置变化(如屏幕旋转)依然存在。因为一个活动
将被销毁并重新创建时,配置的变化情况,这是很难设计之一,将跟踪线程或的AsyncTask
。在另一方面,该系统需要重新连接照顾一个持续片段
到正确的活动
在另一端(所以说话)的配置变化。你仍然可以使用线程或的AsyncTask
,只是现在的片段
拿着它来代替。
A Fragment
instance can persist through device configuration changes (like screen rotation). Because an Activity
will be destroyed and recreated when a configuration change happens, it's difficult to design one that will keep track of a thread or AsyncTask
. On the other hand, the system takes care of reattaching a persisted Fragment
to the proper Activity
at the other end (so to speak) of the configuration change. You would still be using a thread or AsyncTask
, only now the Fragment
is holding it instead.
可能还有其他用途,但有一个我能想到的。
There may be other uses for it, but there's the one I can think of.
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